Membrane fluctuations of human red blood cells investigated by the current signal noise in scanning ion conductance microscopy

Human red blood cells show submicron membrane fluctuations (CMFs) that have been mainly studied with optical microscopies. Although the functional role of this phenomenon is still uncertain, the amplitude of membrane fluctuations is considered as an indicator of mechanical resilience to the stress encountered in the capillary beds. We investigate here the membrane fluctuations in red blood cells using the scanning ion conductance microscopy (SICM), a scanning probe technique that avoids the probe-sample contact. The ion current noise was recorded at a fixed distance from the cell and converted in terms of membrane fluctuation amplitude using as a converting factor the slope of the current-distance curve. We found that CMF amplitude was irreversibly reduced by membrane cross-link. Both whole cell and local increase of membrane tension induced a reduction of CMF amplitude. As for the biochemical regulation of membrane dynamics, we observed that the activation of the noradrenergic transduction pathway, via β-receptors, increased the CMF amplitude. We conclude that the CMFs recorded by SICM and those optically recorded on red blood cells share the main features. In addition SICM provides high spatial and temporal resolution as well as the possibility to apply through the glass pipette acting as probe chemical or physical stimuli to the membrane area where the CMFs are recorded.

Influence of intraventricular fibrinolytic therapy with rt-PA on the long-term outcome of treated patients with spontaneous basal ganglia hemorrhage: a case-control study

Over the recent years, fibrinolytic agents have been tested for intraventricular clot fibrinolysis (IVF). Compared with patients who did not receive IVF, administration of rt-PA induces rapid resorption of intraventricular blood and normalization of cerebrospinal fluid (CSF) circulation resulting in a reduced 30-day mortality and beneficial short-term outcome after 3 months. Our objective was to analyze possible influences of IVF on the long-term outcome after 12 months. Based on a prospective data base, patients with ganglionic supratentorial hematoma with additional intraventricular hemorrhage and occlusive hydrocephalus (n = 135) were isolated. Twenty-seven patients received IVF. To design a case-control study, we carefully matched 22 controls without IVF with regard to hematoma volume, Graeb score, Glasgow Coma Scale on admission and age (five patients remained unmatchable). We determined clinical and imaging parameters by reviewing the medical records and CT scans of all included patients. Outcome after 12 months was evaluated using the modified Rankin scale (mRS). One multivariate regression analysis was performed to determine predisposing factors for outcome. IVF significantly reduced Graeb score during treatment (eight on admission, three after IVF, one prior to discharge in the treated group versus 8/6/2 in patients without IVF). In patients with IVF requirement, a second external ventricular drainage (EVD) and a ventriculoperitoneal (VP) shunt were reduced (P = 0.08) and the incidence of a lumbar drainage was significantly higher (P < 0.01), whilst the overall time of extra-corporal CSF drainage was comparable. EVD associated complications were equal in both groups. Overall long-term outcome was poor but no significant differences were found between patients with and without IVF (mRS 4-6: 12/22 (54%) in patients with and 13/22 (59%) in patients without IVF; P = 0.81). The five excluded patients with IVF were similar to the 22 included ones with respect to imaging findings and outcome. The multivariate analysis revealed age and baseline hematoma volume, but not IVF to significantly impact the outcome. In accordance with previous studies, IVF hastened clot lysis and reduced the need for repeated EVD exchanges and permanent shunting. However, despite these advantages, IVF did not influence long-term outcome after 12 months. The results of the prospective randomized trial (Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage) need to be awaited.

Resolving surface details with reflection and fluorescence video-confocal profilometry

Video-confocal profilometry has been exploited to characterize reflecting and non-reflecting surfaces in materials with tilted and corrugated areas. An alternative method based on fluorescence detection has been developed and tested to characterize metal surfaces modified by intense laser irradiation. Combined representations of surface topography have been obtained on the basis of both reflectance and fluorescence signals. A discussion of results and problems encountered in reflection and fluorescence based techniques is provided.

Temporal and spatial evolution of a laser-induced plasma from a steel target

The space and time evolution of a laser-induced plasma from a steel target has been studied using optical time-of-flight and shadowgraphic techniques. The results, obtained for two distinct laser energy regimes, allow us to individuate two different regions in the plume, one characterized by air and continuum emissions produced by the shock wave ionization and the other characterized by emissions from ablated material. Moreover, it was shown that a sufficiently high laser fluence and short delay time of acquisition are needed to avoid inhomogeneous effects in the plasma, as required in analytical applications such as laser-induced breakdown spectroscopy.

Autoimmune hemolytic anemia in chronic hepatitis C virus infection: an unusual extrahepatic autoimmune manifestation

We report a case of Coombs positive autoimmune hemolytic anemia occurring in a patient with chronic hepatitis C, never treated with interferon-alpha. Prednisone treatment induced the complete remission of both clinical and hematological findings after 2 months. The indirect Coombs test turned negative, while the direct Coombs test remained weakly positive. Autoimmune hemolytic anemia during chronic hepatitis C has been reported to develop only after or simultaneously with interferon-alpha therapy. After discarding other possible causes such as drugs, infectious, neoplastic, lymphoproliferative diseases, and essential mixed cryoglobulinemia, we made the hypothesis of a correlation between autoimmune hemolytic anemia and hepatitis C virus infection.

ALK-negative anaplastic large cell lymphoma and Hodgkin's disease of nodular sclerosing type in 2 siblings

Familial clustering of Hodgkin's disease (HD) and increased risk of developing the disease among the siblings of affected patients suggest that both environmental and genetic factors may play an important role in its pathogenesis. An association between Epstein-Barr virus (EBV) and HD has been widely demonstrated. Recently, latent membrane protein of EBV has also been detected in CD30-positive anaplastic large cell lymphoma. Familial aggregation of HD and a three- to seven-fold-increased risk among the siblings of affected patients suggest increased genetically determined susceptibility. No data about genetic factors are available for anaplastic large-cell lymphoma. In this study, the authors report the case of a woman with anaplastic-lymphoma-kinase (ALK)-negative CD30-positive anaplastic large cell lymphoma, whose brother had developed HD 11 years previously. The clinical, histologic, and immunohistochemical features of the 2 lymphomas were studied. Both siblings showed bulky mediastinal involvement, effacement of normal lymph node architecture by large, atypical cells, resembling Reed-Sternberg cells, expression of EBV latent membrane protein-1 in the lymph node specimens, concordance of both HLA classes I and II. The clinical presentations and immunological studies disclose numerous similarities between the 2 cases and can suggest that their association is not fortuitous. At present, in problematic cases, a combination of morphologic, immunophenotypic and genetic studies may contribute to better define the tumour type.

Acquired factor VIII inhibitor associated with prostatic cancer: successful treatment with steroid and immunosuppressive therapy

Factor VIII inhibitors are antibodies of the IgG class that block functional epitopes or antigenic sites of factor VIII. They occur in about 5-20% of hemophilia A patients after infusions of factor VIII concentrate. Antibodies to factor VIII can also arise spontaneously in association with various autoimmune and chronic inflammatory diseases, hematologic malignancies, solid tumors, certain drugs, dermatologic conditions, and in puerperium. In the majority of cases, the clinical course is characterized by severe hemorrhages. Strategies to treat such inhibitors are controversial. We present the case of a patient with prostatic cancer who developed acquired factor VIII inhibitor. His severe bleeding complications were treated successfully with cyclophosphamide in combination with methylprednisolone. Within a few months, moreover, the immunosuppressive therapy brought about complete disappearance of the inhibitor and normalization of coagulation parameters. Our case illustrates that, although the clinical course in patients with acquired factor VIII inhibitor is not predictable, and the inhibitor may disappear spontaneously, combined therapy with cyclophosphamide and methylprednisolone should be considered for patients with severe hemorrhages.

The relationship between splenic marginal zone B-cell lymphoma and chronic liver disease associated with hepatitis C virus infection

An etiologically important role has been suggested for hepatitis C virus infection in the development of low-grade B-cell non-Hodgkin's lymphoma, such as splenic marginal zone B-cell lymphoma. We present a study of 3 patients with splenic marginal zone B-cell lymphoma and chronic hepatitis C, and describe clinical, histologic, and immunohistochemical features and the response to therapy in these cases. All 3 patients underwent splenectomy, polychemotherapy and alpha-interferon therapy. The first patient achieved complete remission; the second died of hepatic failure and anasarca 3 months after admission; as this writing, the third remains in complete remission 4.5 years after diagnosis. In the second patient, a long latency period of chronic hepatitis C virus infection was observed. Our data indicate that when early detection of the disease is possible, splenic marginal zone B-cell lymphoma has a relatively favorable prognosis. Our results could furthermore suggest an etiologic role for hepatitis C virus infection in the development of splenic B-cell lymphoma through multistep cooperating events. A fuller understanding of the virus-related mechanisms of lymphoproliferation could contribute significantly to the development of new therapeutic strategies.